The invention relates to a machine bed having two guides lying in separate planes and having two guides ways each, namely an approximately horizontal main guide, e.g., for the headstock and tailstock of a turning machine, and a guide at an angle thereto, for machine tools such as turning machines, milling machines, boring machines and the like, having several machine component groups such as headstock, tailstocks, tool rests, center rests, tool turrets, saddles, steady rests, coolant feeding means, manipulating means and the like. At least the guide ways of the main guide lie on intersecting tangents or parallels to tangents of a circle whose center is the same as the center of rotation of the workpiece and/or tool of the machine.
Machine beds for machine tools are known in a variety of forms. The two guides can be constructed with their two guide ways lying in one plane, so that an angle of 180.degree. results between the two planes of guidance of the two guides. The two guides can also be offset from one another by more or less than 180.degree..
All guides having an angle of more than 180.degree. between the two guides have the disadvantage that the distances of the guide ways from the workpiece and/or tool center of rotation are relatively great in comparison to bed guides of less than 180.degree.. This has the disadvantage that the machine components reaching from the bed guides to the center of rotation, such as headstocks, tailstocks, center rests and steady rests, saddles, turrets, slides, coolant feeders, workpiece feeding systems, manipulating means and the like, must have relatively large dimensions, resulting in higher machining costs, greater weights, lower rigidity due to longer lever arms, greater production tolerances and greater thermal expansions.
German Pat. No. 975,695 discloses a machine bed having two guides lying in separate planes, each guide having two guide ways, for machine tools, in which the guide ways of the one guide lie on intersecting tangents of a circle whose center is the same as the center of rotation of the workpiece and/or tool. If, in the case of a turning machine, the main guide which bears the headstock and tailstock is constructed in this manner, a collecting passage can be created between the ways of this guide for the chips formed by the machining.
In such an arrangement of the guide ways of the main guide, torques can occur, in the case of workpieces of great weight and of the occurrence of high machining forces, by which the components carried on the main guide may assume an unstable state or even be exposed to forces tending to lift these components away from the main guide. This can result in chattering and in rough running of the machine while cutting.
The invention is addressed to the problem of constructing the machine of the above-mentioned kind such that a reliable guidance of the components carried on the main guide will result.